bellMode resource

From The x3270 Wiki
Type Default
string beepFlash

Controls how wc3270 responds to a 3270 ALARM WCC or an NVT BEL (U+0007) character. The value beepFlash causes both the Windows console to beep and the wc3270 window to flash; this is the default behavior. The values beep and flash cause just the beep and just the window flash respectively. The value nonecauses ALARM WCCs and BEL characters to be ignored.